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Chinese Journal of Catalysis
2024, Vol. 62
Online: 18 July 2024

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Cover: Using extensive computational studies, Prof. Binju Wang and coworkers have unraveled the mechanism of the non-heme iron enzyme TqaLNc for the selective C–H amination, en route to the aziridine product that are promising for anti-tumor therapy. The study reveals a dynamic catalysis machinery that involves both the conformational switch of the Fe(IV)=O species and the coordination of substrate to Fe atom. This mechanistic scenario rationalizes all available experimental data, emphasizing the crucial roles of the dynamics of both the Fe atom and the substrate in non-heme Fe(II)/KG enzyme-catalyzed C–H functionalization, extending beyond simple hydroxylation. Read more about the article behind the cover on page 131–144.

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Recent progress on bimetallic catalysts for the production of fuels and chemicals from biomass and plastics by hydrodeoxygenation Lujie Liu, Ben Liu, Yoshinao Nakagawa, Sibao Liu, Liang Wang, Mizuho Yabushita, Keiichi Tomishige 2024, 62:  1-31.  DOI: 10.1016/S1872-2067(24)60054-9 Abstract ( 291 )   HTML ( 25 )   PDF (5652KB) ( 133 )   Valorization of biomass and plastics is an urgent assignment to achieve the goal of carbon neutrality. Hydrodeoxygenation using bimetallic catalysts with distinct active sites is one of the most effective approaches to producing fuels and chemicals via C-O/C-C bonds hydrogenolysis and hydrogenation. Rational design of bimetallic catalysts has been progressed in recent studies owing to the understanding of synergy and strong mutual interaction between metal nanoparticles and metal oxide species. Thus, activity of bimetallic catalysts has been further improved, and the chemoselectivity for suppression of C-C bond dissociation and the regioselectivity among different C-O bonds, which have less been achieved before, are realized in the hydrodeoxygenation reactions. The catalytic performances, catalyst structures, and reaction mechanisms are directly compared and discussed in details based on the C-O bond cleavage using glycerol and 1,2-propanediol hydrogenolysis as model reactions over Ir-, Pt-, and Ru-based bimetallic catalysts. Finally, application of these bimetallic catalysts to conversion of lignocellulose-derived feedstocks, carbonyl compounds, and typical plastic of polycarbonates is introduced.

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Progress in tracking electrochemical CO2 reduction intermediates over single-atom catalysts using operando ATR-SEIRAS Jing Yan, Jiaqi Ni, Hongli Sun, Chenliang Su, Bin Liu 2024, 62:  32-52.  DOI: 10.1016/S1872-2067(24)60068-9 Abstract ( 327 )   HTML ( 36 )   PDF (13640KB) ( 152 )   Owing to the multiple proton-coupled electron transfer steps involved in the electrochemical carbon dioxide reduction reaction (CO2RR), single-atom catalysts (SACs) are ideal platforms for studying such complex chemical reaction processes. The structural simplicity and homogeneity of SACs facilitate the understanding of the structure-performance relationship and reaction mechanisms of the CO2RR. Operando attenuated total reflection surface-enhanced infrared absorption spectroscopy (ATR-SEIRAS) is a valuable tool to identify the dynamic intermediate transformation processes in the CO2RR occurring on SACs and to study the impact of local reaction environments on the CO2RR performance. This article reviews operando ATR-SEIRAS and its key applications in the SAC-catalyzed CO2RR. The review briefly introduces the surface enhancement mechanism of electrochemical in situ infrared spectroscopy, formation mechanisms of the C1 and C2 products, function of operando ATR-SEIRAS in investigating the mechanisms of single-/dual-atom catalysts in converting CO2/CO to C1 and C2 products, and methods of using spectroscopic information to determine the interfacial H2O and local pH at the electrode. Finally, the review provides perspectives on the future development of operando ATR-SEIRAS.

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Recent advances of the catalysts for photoelectrocatalytic oxygen evolution and CO2 reduction reactions Hong-Rui Zhu, Hui-Min Xu, Chen-Jin Huang, Zhi-Jie Zhang, Qi-Ni Zhan, Ting-Yu Shuai, Gao-Ren Li 2024, 62:  53-107.  DOI: 10.1016/S1872-2067(24)60053-7 Abstract ( 214 )   HTML ( 12 )   PDF (17237KB) ( 90 )   Increasing global energy consumption and environmental pollution make the use of new energy sources and environmentally friendly technologies essential to meet the diverse needs of industries. Photoelectrocatalysis is a promising method of utilising solar and electrical energy for various catalytic reactions with significant environmental and energy saving benefits. And photoelectrocatalytic (PEC) oxygen evolution reaction (OER) and CO2 reduction reaction (CO2RR) are two catalytic reactions with great potential for energy and environmental applications. PEC OER is critical for renewable energy technologies for water oxidation and other related oxidation reactions. PEC CO2RR converts carbon dioxide into high-value products via a catalyst, enabling the rational use of carbon dioxide and the reduction of greenhouse gas emissions. Both technologies are efficient, environmentally friendly, and sustainable. However, further research and optimisation are needed to promote the industrial application of both technologies for energy conversion and environmental protection. This paper reviews the research progress of PEC CO2RR and OER catalysts in recent years, including detailed descriptions of catalyst types, reaction mechanisms and performance tests. Finally, the paper considers the future trends and prospects of PEC technology, providing new insights into the technology and research directions for PEC OER and CO2RR catalysts.

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Development of efficient catalysts for selective hydrogenation through multi-site division Xiaomin Ren, Huicong Dai, Xin Liu, Qihua Yang 2024, 62:  108-123.  DOI: 10.1016/S1872-2067(24)60049-5 Abstract ( 211 )   HTML ( 13 )   PDF (8532KB) ( 113 )   Heterogeneous hydrogenation with supported metal catalyst is one of the efficient methods for producing fine chemicals. Hydrogenation reactions for fine chemical production often use reactants with more than one unsaturated bond or involve cascade multiple-step reactions, facing the dilemma of activity and selectivity. The dual-site or multi-site catalysts have been employed to solve this dilemma, but the entanglement at different sites generally cannot improve selectivity without reducing activity. In this review, we will introduce recent progresses in the construction of dual-site supported metal catalysts with division of active site, which may break the tradeoff between activity and selectivity in selective hydrogenation considering that each active sites can be modulated separately without causing the property variation of other sites. In addition, such catalysts contribute to the basic understanding of their structure-activity relationship and provide a theoretical basis for the development of efficient hydrogenation catalysts for fine chemical production.

Communication

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Isomerization of methylenedianilines using shape-selective zeolites Sam Van Minnebruggen, Ka Yan Cheung, Trees De Baerdemaeker, Niels Van Velthoven, Matthias Degelin, Galahad O’Rourke, Hiroto Toyoda, Andree Iemhoff, Imke Muller, Andrei-Nicolae Parvulescu, Torsten Mattke, Jens Ferbitz, Qinming Wu, Feng-Shou Xiao, Toshiyuki Yokoi, Nils Bottke, Dirk De Vos 2024, 62:  124-130.  DOI: 10.1016/S1872-2067(24)60071-9 Abstract ( 123 )   HTML ( 11 )   PDF (2268KB) ( 41 )   Supporting Information Methylenedianilines (MDA) are widely used as intermediates in the production of polyurethanes and polyisocyanurates. The current routes for the production of MDA offer only limited control of the isomer ratio (4,4’/(2,4’+2,2’)), with 4,4’-MDA being the most valuable isomer. While 2,4’-MDA is also marketed, significant added value could be unlocked upon further steering the production towards 4,4’-MDA. We here show that zeolites such as Beta can selectively isomerize 2,4’-MDA towards the desired 4,4’-MDA via a bimolecular mechanism, in an aniline background. While several acid zeolites were found to be active isomerization catalysts, MCM-68 (MSE topology) in particular combines high isomerization activity with efficient shape-selective suppression of the formation of unwanted 2,2’-MDA and oligomers. The origin of this shape-selectivity was studied, highlighting the crucial role of the acid site location in the pore confinement of MSE zeolites.

Articles

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Coordination dynamics of iron enables the selective C-N coupling but bypasses unwanted C-H hydroxylation in Fe(II)/α-ketoglutarate- dependent non-heme enzymes Xuan Zhang, Jia Liu, Langxing Liao, Zikuan Wang, Binju Wang 2024, 62:  131-144.  DOI: 10.1016/S1872-2067(24)60064-1 Abstract ( 213 )   HTML ( 13 )   PDF (2483KB) ( 112 )   Supporting Information Non-heme Fe(II)/α-ketoglutarate (αKG)-dependent enzymes catalyze numerous C-H activation and functionalization reactions. However, how αKG-dependent non-heme enzymes catalyzed C-H functionalization beyond the hydroxylation is largely unknown. Here, we addressed this issue in Fe(II)/ αKG-dependent oxygenase TqaLNc, which catalyzes the selective C-H amination but bypasses the thermodynamically favored C-H hydroxylation. Here, the extensive computational studies have shown that the aziridine formation involves the conformational change of the Fe(IV)=O species from the axial configuration to the equatorial one, the substrate deprotonation of NH3+ group to form the NH-ligated intermediate, the C-H activation by the equatorial Fe(IV)=O species. Such mechanistic scenario has been cross-validated by oxidation of various substrates by TqaLNc and its variants, including the available experiments and our new experiments. While the presence of steric hindrance between the substrate and the second-sphere residues would inhibit the aziridination process, the intrinsic reactivity of aziridination vs. hydroxylation is dictated by the energy splitting between two key redox-active dπ* frontier molecular orbitals: dπ*Fe-N and dπ*Fe-OH. The present findings highlight the key roles of the coordination change and dynamics of iron cofactor in dictating the catalysis of non-heme enzymes and have far-reaching implications for the other non-heme Fe(II)/αKG-dependent enzymes catalyzed C-H functionalization beyond the hydroxylation.

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Surface dynamics of Rh/Al2O3 during propane dehydrogenation Shuyi Li, Changle Mu, Nianqiu He, Jie Xu, Yanping Zheng, Mingshu Chen 2024, 62:  145-155.  DOI: 10.1016/S1872-2067(24)60063-X Abstract ( 164 )   HTML ( 7 )   PDF (8888KB) ( 74 )   Supporting Information The surface structures of heterogeneous catalysts significantly impact catalytic performance, especially for structure-sensitive reactions. In this study, we employed surface techniques such as low-energy ion scattering spectroscopy, X-ray photoelectron spectroscopy, and Fourier transform infrared spectroscopy with CO as a probe (CO-FTIR) to investigate the surface dynamics of Rh/Al2O3 catalysts for propane dehydrogenation (PDH). We observed a notable induction process for PDH on Rh/Al2O3 catalysts, marked by significant variations in propane conversion, methane, and propylene selectivities. These changes were attributed to substantial coke formation. Aberration-corrected high-angle annular dark-field scanning transmission electron microscopy) and CO-FTIR revealed the coexistence of Rh nanoparticles, clusters, and single atoms on the surface. Through various dynamic quasi in-situ characterizations, we found that coke preferentially covered Rh clusters, thereby inhibiting C-C bond breaking and methane formation. Meanwhile, Rh single atoms were less affected by coke coverage and remained exposed as active and selective sites for PDH, favoring propylene production. This work underscores the sensitivity of PDH to the sizes of Rh species, with isolated Rh single atoms promoting propylene formation.

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An efficient and stable high-entropy alloy electrocatalyst for hydrogen evolution reaction Gui Zhao, Kuan Lu, Yunan Li, Fagui Lu, Peng Gao, Bing Nan, Lina Li, Yixiao Zhang, Pengtao Xu, Xi Liu, Liwei Chen 2024, 62:  156-165.  DOI: 10.1016/S1872-2067(24)60067-7 Abstract ( 457 )   HTML ( 19 )   PDF (4548KB) ( 172 )   Supporting Information High-entropy alloy (HEA) catalysts exhibit enhanced hydrogen evolution reaction (HER) activity in water electrolysis, yet the understanding of their structure and active sites in reaction environments remains unclear. Here, we systematically investigated the HER activity and stability of PtPdRhRuCu/C through a combination of electrochemical measurements, in situ synchrotron radiation X-ray absorption spectroscopy (XAS) at the Cu K-edge and Pt L3-edge, and density functional theory (DFT) calculations. Uniformly sized PtPdRhRuCu HEA nanoparticles were prepared via a facile one-step solvothermal method. In situ XAS results revealed that the HEA nanoparticles maintained metallic states and a disordered arrangement of the overall structure at hydrogen evolution potential, implying the absence of the separated phases. Relying on multi-metal active sites, PtPdRhRuCu/C demonstrated a remarkably low overpotential of 23.3 mV at 10 mA cm-2 in alkaline HER, which is significantly lower than the overpotential observed in commercial Pt/C (50.3 mV), and achieving a mass activity 7.9 times that of Pt/C. DFT calculations show that the synergy of each metal site optimizes the dissociation energy barrier of water molecules. This study not only demonstrates the advancement of high-entropy alloys in electrocatalysis but also provides a comprehensive understanding of the structure-activity relationship of these unique catalysts through detailed characterizations. Our findings further contribute to the rational design and application of high-entropy alloy catalysts, specifically in HER.

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Manganese pyrophosphate with multiple coordinated water molecules for electrocatalytic water oxidation Shujiao Yang, Pengfei Jiang, Kaihang Yue, Kai Guo, Luna Yang, Jinxiu Han, Xinyang Peng, Xuepeng Zhang, Haoquan Zheng, Tao Yang, Rui Cao, Ya Yan, Wei Zhang 2024, 62:  166-177.  DOI: 10.1016/S1872-2067(24)60052-5 Abstract ( 142 )   HTML ( 4 )   PDF (3649KB) ( 47 )   Supporting Information The coordinated water in the Mn4CaO5 clusters in natural water oxidation center is believed to play an important role in promoting water oxidation. However, its specific role is unclear. In this work, based on a new manganese phosphate (Mn2P2O7·3H2O) with well-defined crystal surfaces (crystalline MnPi) and its amorphous counterpart (amorphous MnPi), the effects of coordinated water molecules on water oxidation have been systematically investigated. There are four coordinated water molecules on one Mn site, which is very rare and valuable to study relevant effects from water coordination. Unusually, the crystalline MnPi outperformed the amorphous MnPi in electrocatalysis. The exposed well-defined surface of the crystalline MnPi contains continuous Mn sites with multiple coordinated water molecules. The kinetics and thermodynamics of surface oxidation have been quantitatively studied based on the appealing catalyst platform. The interaction between adjacent Mn sites leads to a 3H+/2e dual site oxidation in crystalline MnPi, while this process is 2H+/1e single site conversion in amorphous MnPi. The higher level of charge neutralization of oxygen atoms from continuous H-bond network in crystalline MnPi is helpful for the MnII/III oxidation, which subsequently promotes water oxidation. This study provides valuable insight into the role of coordinated water molecules in initiating water oxidation in Mn-based catalytic systems.

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Abstracting photogenerated holes from covalent triazine frameworks through carbon dots for overall hydrogen peroxide photosynthesis Weijie Ren, Ning Li, Qing Chang, Jie Wu, Jinlong Yang, Shengliang Hu, Zhenhui Kang 2024, 62:  178-189.  DOI: 10.1016/S1872-2067(24)60050-1 Abstract ( 138 )   HTML ( 3 )   PDF (4682KB) ( 50 )   Supporting Information Owing to the rapid recombination of photogenerated electron-hole pairs with strong Coulomb interactions, the photocatalytic activity of metal-free conjugated polymers is often unsatisfactory. This article reports a simple method for incorporating carbon dots (CDs) into highly crystalline covalent triazine frameworks (CTFs) by directly heating a pretreated mixture of 1,4-dicyanobenzene, CDs, and alkali metal salts in air. The resultant photocatalyst exhibits a H2O2 production rate, solar-to-chemical conversion efficiency, and apparent quantum yield of 2464 μmol h-1 g-1, 0.9% at full spectrum, and 13% at 500 nm, respectively, surpassing most reported photocatalysts. The results of this study reveal that CDs can serve as hole extractors to efficiently drive exciton dissociation and can offer active sites for water oxidation reactions. This study is also the first to observe that alkali metal ions can interact with the carboxylic acid groups on the surface of CDs during synthesis to enhance the hole-extraction ability of CTFs, thereby accelerating photocatalytic H2O2 production. This study provides insights into the rational design of highly efficient CDs-based photocatalysts.

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Proton feeding from defect-rich carbon support to cobalt phthalocyanine for efficient CO2 electroreduction Ziwen Mei, Kejun Chen, Yao Tan, Qiuwen Liu, Qin Chen, Qiyou Wang, Xiqing Wang, Chao Cai, Kang Liu, Junwei Fu, Min Liu 2024, 62:  190-197.  DOI: 10.1016/S1872-2067(24)60061-6 Abstract ( 176 )   HTML ( 13 )   PDF (9198KB) ( 98 )   Supporting Information Electrocatalytic CO2 reduction reaction (CO2RR) holds significant promise for sustainable energy conversion, with cobalt phthalocyanine (CoPc) emerging as a notable catalyst due to its high CO selectivity. However, CoPc's efficacy is hindered by its limited ability to provide sufficient proton for the protonation process, particularly at industrial current densities. Herein, we introduce defect-engineered carbon nanotubes (d-CNT) to augment proton feeding for CO2RR over CoPc, achieved by expediting water dissociation. Our kinetic measurements and in-situ attenuated total reflection surface-enhanced infrared absorption spectroscopy reveal d-CNT significantly enhances proton feeding, thereby facilitating CO2 activation to *COOH in CoPc. Density functional theory calculations corroborate these findings, illustrating that d-CNT decreases the barrier to water dissociation. Consequently, the CoPc/d-CNT mixture demonstrates robust performance, achieving 500 mA cm-2 for CO2RR with CO selectivity exceeding 96%. Notably, CoPc/d-CNT remains stability for a duration of 20 h under a substantial current density of 150 mA cm-2. The study broadens the scope of practical applications for molecular catalysts in CO2RR, marking a significant step towards sustainable energy conversion.

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Asymmetric oxygen vacancies in La2FeMO6 double perovskite for boosting oxygen activation and H2S selective oxidation Zheng Wei, Guoxia Jiang, Yiwen Wang, Ganggang Li, Zhongshen Zhang, Jie Cheng, Fenglian Zhang, Zhengping Hao 2024, 62:  198-208.  DOI: 10.1016/S1872-2067(24)60051-3 Abstract ( 168 )   HTML ( 7 )   PDF (4998KB) ( 64 )   Supporting Information Tuning oxygen vacancy (VO) in metal oxides catalysts that efficiently activates O2 molecule to promote oxidation reactions remains challenging. Herein, transition metal (M = Mn, Co, and Mo) doping was used to moderate the coordination environment of VO in La2FeMO6 and promote activity for selective oxidation of hydrogen sulfide (H2S). Various techniques reveal that the introduction of Mn and Co forms the homogeneous double perovskite phase, which results in the formation of asymmetric VO. Although these asymmetric VO are more difficult to form than symmetric Fe-VO-Fe due to the shorter bond distance and stronger bond strength of Fe-O, they are more conducive to the dissociation of O2 molecules. Among them, the formed rich Fe-VO-Mn sites from the alternate substitution of Mn to Fe boosted the activation of O2 molecules of Mn-substituted LaFeO3. Therefore, enhanced catalytic activity and outstanding sulfur selectivity were achieved as a result of promoted oxygen mobility and reducibility. This work provides an attractive strategy for rational design of advanced oxidation catalysts.

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An oxygen-vacancy-rich polyoxometalate-aided Ag-based heterojunction electrocatalyst for nitrogen fixation Xinyu Chen, Cong-Cong Zhao, Jing Ren, Bo Li, Qianqian Liu, Wei Li, Fan Yang, Siqi Lu, YuFei Zhao, Li-Kai Yan, Hong-Ying Zang 2024, 62:  209-218.  DOI: 10.1016/S1872-2067(24)60046-X Abstract ( 216 )   HTML ( 18 )   PDF (4822KB) ( 76 )   Supporting Information Polyoxometalates (POMs) with well-defined molecular structures are sustainable and promising catalysts for reducing nitrogen to ammonia under ambient conditions. In this study, oxygen-vacancy-rich AgPW11/Ag nanocube catalysts were synthesized via a one-pot method using POMs, reductants, and inducers. The oxygen-vacancy-rich AgPW11/Ag heterojunction catalyst exhibited a significant ammonia yield as high as 46.02 ± 1.03 μg h-1 mg-1cat. and faradaic efficiency of 34.07 ± 0.16% at a potential of -0.2 V (vs. RHE), maintaining stable catalysis for 32 h without decay and greatly outperforming the Ag catalyst. The excellent catalytic performance and mechanism were established using density functional theory calculations. The robust interaction between the d orbitals of the Ag atom in AgPW1112e and π* orbitals of N2 activates the adsorbed N2 and promotes the conversion of the first protonation process *N2 to *N-NH (the potential determination step). This study provides a new avenue for designing stable Ag-based catalysts for nitrogen fixation.

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Synergistic photoelectric and thermal effect for efficient nitrate reduction on plasmonic Cu photocathodes Zhenlin Chen, Jing Xue, Lei Wu, Kun Dang, Hongwei Ji, Chuncheng Chen, Yuchao Zhang, Jincai Zhao 2024, 62:  219-230.  DOI: 10.1016/S1872-2067(24)60060-4 Abstract ( 236 )   HTML ( 12 )   PDF (3132KB) ( 68 )   Supporting Information Recently, electrochemical nitrate reduction reaction (NO3RR) has been intensively explored for the synthesis of ammonia, and copper (Cu) has become one of the most promising materials for NO3RR. Notably, Cu is an important plasmonic metal that absorbs visible light. The plasmonic effect might have a significant influence on the performance of Cu-catalyzed NO3RR but has been seldom reported. Herein, we report the synergistic photoelectric and thermal effect for efficient and stable NO3RR on plasmonic Cu nanowire photocathodes, which is exclusively effective for NO3RR but has no effect on the competing hydrogen evolution reaction. The faradaic efficiency for ammonia production is nearly 100% within a potential range from −0.2 V to −0.4 V vs. RHE, and a high ammonia yield rate of 1.37 mmol h−1 cm−2 is achieved at −0.2 V vs. RHE. Further operando photoelectrochemical studies and theoretical simulations confirm that the plasmonic excitation efficiently accelerates the rate-limiting desorption of NH3 on Cu surfaces. We further demonstrate the versatility of this strategy to other Cu-based nanostructures.

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Manipulating the interactions between N-intermediates and one-dimensional conjugated coordination polymers to boost electroreduction of nitrate to ammonia Qing Liu, Xue-Feng Cheng, Jin-Yan Huo, Xiao-Fang Liu, Huilong Dong, Hongbo Zeng, Qing-Feng Xu, Jian-Mei Lu 2024, 62:  231-242.  DOI: 10.1016/S1872-2067(24)60059-8 Abstract ( 149 )   HTML ( 9 )   PDF (3450KB) ( 56 )   Supporting Information Electrocatalytic reduction of nitrate to ammonia (NITRR) is a promising strategy to remove nitrate pollutants and generate ammonia under mild conditions. However, the low conversion rate of nitrate and insufficient ammonia production rate severely limits the development of NITRR. Manipulating the adsorption of N-intermediates on the surface of catalyst greatly affects the activity and the selectivity of catalytic reaction. Herein, four one-dimensional π-d conjugated coordination polymers (1D CCPs) are synthesized and applied to NITRR. The selectivity and activity of NITRR are well improved by metal ion substitutions, which regulate the adsorption towards generated intermediates. The ammonia production rate reaches 2.28 mg h-1 cm-2 over Cu-BTA in 2 h, comparable to recent works at low nitrate concentrations, and the conversion rate of nitrate up to 96.74% in four hours with 79.46% ammonia selectivity. Density functional theory calculations reveal that Cu-BTA had electron-richer Cu center, causing the enhanced free energy of *NO and the attenuation of N=O bond. Therefore, the ΔG required for converting *NO to *NHO is reduced and the further hydrogenation is promoted. Additionally, the adsorption energies toward NH3 are also effectively reduced by metal ions substitution, accelerating the desorption of generated and adsorbed NH3, making the turnover of catalysts more frequent.

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Rational design of Pt-anchored single-atom alloy electrocatalysts for NO-to-NH3 conversion by density functional theory and machine learning Jieyu Liu, Haiqiang Guo, Yulin Xiong, Xing Chen, Yifu Yu, Changhong Wang 2024, 62:  243-253.  DOI: 10.1016/S1872-2067(24)60078-1 Abstract ( 416 )   HTML ( 14 )   PDF (3628KB) ( 177 )   Supporting Information Electrochemical NO reduction reaction (NORR) toward NH3 synthesis emerges as a promising approach to eliminate NO pollution and generate high-value-added products simultaneously. Therefore, exploring suitable NORR electrocatalysts is of great importance. Here, we present a design principle to evaluate the activity of single-atom alloy catalysts (SAACs), whose excellent catalytic performance and well-defined bonding environments make them suitable candidates for studying structure-activity relationships. The machine learning (ML) algorithm is chosen to unveil the underlying physics and chemistry. The results indicate that the catalytic activity of SAACs is highly correlated with the local environment of the active center, that is, the atomic and electronic features. The coeffect of these features is quantitatively verified by adopting a data-driven method. The combination of density functional theory (DFT) and ML investigations not only provides an understanding of the complex NORR mechanisms but also offers a strategy to design highly efficient SAACs with specific active centers rationally.

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Large-current polarization-engineered FeOOH@NiOOH electrocatalyst with stable Fe sites for large-current oxygen evolution reaction Qingyun Lv, Weiwei Zhang, Zhipeng Long, Jiantao Wang, Xingli Zou, Wei Ren, Long Hou, Xionggang Lu, Yufeng Zhao, Xing Yu, Xi Li 2024, 62:  254-264.  DOI: 10.1016/S1872-2067(24)60062-8 Abstract ( 206 )   HTML ( 3 )   PDF (19593KB) ( 67 )   Supporting Information NiFe-based (oxy)hydroxides are among the most efficient electrocatalysts for the oxygen evolution reaction (OER). However, significant Fe leakage during the OER results in unsatisfactory stability. Herein, a large-current (1.5 A cm−2) galvanostatic reconstruction was used to fabricate FeOOH@NiOOH (eFNOL) with both fixed Fe sites and exposed high-index crystal facets (HIFs). Compared to FeNiOOH with low-index crystal facets, the phase-separated FeOOH@NiOOH showed a higher binding energy towards Fe, and the HIFs significantly improved the catalytic activity of FeOOH. The optimized eFNOL catalyst exhibits ultralow overpotentials of 234 and 272 mV, yielding substantial current densities of 100 and 500 mA cm−2, respectively, with a small Tafel slope of 35.2 mV dec−1. Moreover, due to the stabilized Fe sites, its striking stability over 100 h at 500 mA cm−2 with 1.5% decay outperforms most NiFe-based OER catalysts reported recently. This study provides an effective strategy for developing highly active and stable catalysts via large-current electrochemical reconstruction.

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Quenching to optimize the crystalline/amorphous ratio of CoPS nanorods for hydrazine-assisted total water decomposition at ampere-level current density Xiao Chen, Yunmei Du, Yu Yang, Kang Liu, Jinling Zhao, Xiaodan Xia, Lei Wang 2024, 62:  265-276.  DOI: 10.1016/S1872-2067(24)60044-6 Abstract ( 86 )   HTML ( 3 )   PDF (3611KB) ( 22 )   Supporting Information Directional construction of crystalline/amorphous (c/a)-phosphosulfide heterostructures with exceptional intrinsic activity through a facile strategy is challenging. In this study, we synthesized q-CoPS nanorods with a unique c/a-CoPS core-shell heterostructure through the ‘gas-phase phosphorus vulcanization-quenching’ treatment. This work also innovatively masters the regulation of the initial quenching temperature to alter the c/a ratio of the CoPS nanorods. Surprisingly, with increasing initial quenching temperature, the area of the amorphous CoPS shell gradually increases. Density functional theory calculations reveal that the Co sites at the c/a-heterointerface, as the difunctional c/a-interface active site, effectively optimize the kinetics of the hydrogen evolution reaction (HER) and hydrazine oxidation reaction (HzOR). As anticipated, q-CoPS/CF requires an overpotential of only 90 mV at a current density of 1000 mA cm-2 for the alkaline HER, which is much lower than that required using the state-of-the-art Pt/C catalyst. Additionally, q-CoPS/CF achieves a current density of 1000 mA cm-2 at only 0.06 V in the HzOR. Overall, this work proposes an efficient strategy for developing a bifunctional electrocatalyst with a unique c/a-heterostructure to address future energy needs.

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Synergy of charge migration direction-manipulated Z-scheme heterojunction of BiVO4 quantum dots/perylenetetracarboxylic acid and nanosized Au modification for artificial H2O2 photosynthesis Teng Liang, Yutong Li, Shuai Xu, Yuxin Yao, Rongping Xu, Ji Bian, Ziqing Zhang, Liqiang Jing 2024, 62:  277-286.  DOI: 10.1016/S1872-2067(24)60058-6 Abstract ( 136 )   HTML ( 3 )   PDF (4046KB) ( 33 )   Supporting Information Herein, perylenetetracarboxylic acid (PTA) nanosheets with anisotropic charge migration driven by the formed internal electric fields are synthesized through a facile hydrolysis-reassembly process. Strategically, a Z-scheme heterojunction with free-flowing interfacial charge transfer and spatially separated redox centers is constructed based on the distinct photogenerated electrons and holes accumulation regions of PTA nanosheets by in-situ introducing BiVO4 quantum dots (BQD) and nanosized Au. The optimized BQD/PTA-Au exhibits a ca. 6.4-fold and 4.8-fold enhancement in H2O2 production rate and apparent quantum yield at 405 nm compared with pristine PTA, respectively. The exceptional activities are attributed to the cascade Z-scheme charge transfer followed the matched charge migration orientation, as well as the Au active sites for accelerating 2e− oxygen reduction pathway induced by superoxide radicals, as unraveled by electron paramagnetic resonance, in-situ irradiated X-ray photoelectron spectroscopy and in-situ diffuse reflectance infrared Fourier transformation spectroscopy. This work provides a strategy to design an efficient Z-scheme system towards solar-driven H2O2 production.

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Self-supported film catalyst integrated with multifunctional carbon nanotubes and Ni-Ni(OH)2 heterostructure for promoted hydrogen evolution Wancheng Zhao, Jiapeng Ma, Dong Tian, Baotao Kang, Fangquan Xia, Jing Cheng, Yajun Wu, Mengyao Wang, Gang Wu 2024, 62:  287-295.  DOI: 10.1016/S1872-2067(24)60057-4 Abstract ( 159 )   HTML ( 10 )   PDF (4917KB) ( 48 )   Supporting Information In order to reduce energy consumption in water electrolysis, it is of great importance to design active and stable electrocatalysts for hydrogen evolution reaction (HER) in alkaline solution, especially based on earth-abundant metal. Here we integrate carbon nanotubes (CNTs) and Ni-Ni(OH)2 heterostructure multifunctional components to design a self-supported 3D CNTs-Ni-Ni(OH)2 catalyst for HER by composite deposition and subsequent in-situ oxidation. In alkaline solution, this designed CNTs-Ni-Ni(OH)2 catalyst exhibits 0 mV onset overpotential, and overpotentials of 65 mV and 109 mV at 10 and 50 mA/cm2 respectively. Electrochemical measurements, characterizations, and simulation results attribute the outstanding performance to the incorporation of CNTs and heterostructure. CNTs induce the formation 3D catalytic surface, enhance electrochemical active surface area, and more importantly weaken the adsorption of H. Moreover, the formation of heterostructure, especially reversible Ni(OH)2, supplies active sites and adjusts the adsorption strength of H atom to an optimal value. CNTs and heterostructure synergistically facilitate water adsorption, promote water dissociation, and accelerate H2 desorption. Significantly, integration of multifunctional components supplies a distinct strategy for development of cost-effective electrocatalyst with outstanding performance.